Automatic self-locking differential gearing



' April 14, 1925; 1,533,327

A J. F. MORRISSEY AUTOMATIC SELF LOCKING DIFFERENTIAL GEARING Filed May21. 1923 3 Sheets-Sheet 1 INVEN TOR Jaw/v t Morin/68E) Irroiuvcrs J. F.MoRRissEY AUTOMATIC SELF LOCKING DIFFERENTIAL GEARING April 14,1925.

Filed May 21, 1923 3 Sheets-Sheet 2 [N YEN TOR JOHN E MORE/66E r BY K,fix 722M;

IVTTOR/YEYG April 14, 1925.

. 1,533,327 J. F.'MORRISSEY AUTOMATIC SELF LOCKING DIFFERENTIAL GEARINGFiled May 21. 1923 5 Sheets-Shee't 5 IN YEA/TOR JOHN I. MORE/602')Patented Apr. 14, 1925.

UNITED STATES PATENT OFFICE.

JOHN FR. MORRISSEY, OF ANTIGO, WISCONSIN.

- AUTOMATIC SELF-LOCKING DIFFERENTIAL GEARING.

Application filed" Maya 1, 1923. Serial No. 640,437.

' following is a specification.

- or engage a slippery spot in the surface of- This invention relates tolmprovements in differential gearing such as is commonly used inconnection with automobiles, or power propelled vehicles, and has aspecific object to provide means for automatical- 1y locking both of thedriven wheels or members together to as to rotate as a unit, when thereis a tendency for either wheel to race or spin, thereby, equallydistributing the power from the motor to both driven wheels.

It is well known that the common type of differentials, universally usedin automobiles permit the driven wheels to rotate relatively atdifferent speeds when turning corners. The above t e of difierentialalso permits the rapid i ling of one driven wheel with reference to theother, should it become disengaged from the ground in some manner,

the road, thereby decreasing its frictional contact with the ground,while the other 1 wheel may be prevented from rotation due to a betterfrictional contact with the ground. When the above condition occurs, itoften becomes impossible to further propel the autamobile or vehicle .byits own power until the above condition has been removed.

.The novel differential gearing herein shown, permits, within apredetermined limit, the usual differential function. However, means arealso provided, whereby, when such limit has been exceeded, thereautomatically results a positive drive for both driven wheels, thuseliminating the difliculty heretofore referred to.

The object of this invention, therefore, is to rovide an'improveddifferential gearing.

(gther objects of the invention will more fully appear from thefollowing detailed description and the accompanying drawings and will bepointed out in the annexed claims.

In the accompanying drawings there has been disclosed a structuredesigned to carry out the objects of the invention but it is to beunderstood that the invention is not con fined to the exact featuresshown, as various changes may be made within the scope of the claimswhich'follow.

In the drawings:

Figure 1 is a horizontal sectional view of a differential and showing myinvention applied thereto;

Figure 2 is fragmentary view, partially -in section and partially inelevation and showing the position of the parts when the driven wheelsare reversed;

Figure 3 is a transverse sectional View on the line 33 of Figure 1;

Figure 4 is a transverse sectional view on the line 4-4 of Figure 1;

Figure 5 is a similar view on the line 5-5 of Figure 1; and

Figure 6 is a fragmentary detail view showing the means provided in thehousing for shifting the position of the carriages.

In the selected embodimentof the invention here shown for the purpose ofdisclosure, there is illustrated a differential housing of usualconstruction comprising a right part 7 and left part 8, joined togetherby bolts 9. The usual bearing 11 is provided at the forward end of thehousin for the drive shaft 12 carrying the usual drive pinions 13 whichengages the bevel ring gear 1 1, secured to the differential case 15,rotatably mounted in anti-friction bearings 16 provided in thedifferential housing. A differential spider 17 is provided within thecase 15 and has radial pins 18, usually three or four in number, securedthereto and projecting outwardly therefrom through apertures provided insaid case.

mounted upon the pins 18 and adapted to be in engagement with thedifferential side pinions 21, preferably provided with outwardly Theusual differentlal or spider pinions 19 are rotatably sleeves, 22rotatably mounted in differential pinions 21 as being integrally formedwith the sleeves 22. They 'may, however, be constructed independently ofthe sleeves and mounted thereon by any suitable means desired. As thetwo sides of the differential are identical it will be necessary todescribe'but one side, like parts being represented by like numerals.

vided on each side .0

A carriage or slide 27 is slid-ably mounted within the sleeve 22 and isprovided with a plurality of' radial pins 28 secured thereto, adjacentits outer end and projecting outwardly therefrom through elongatedapertures 29, in the sleeves. The outer ends of these )ins are adaptedto engage a pair of annuliir grooves 31 and 32, provided in the housing,and function in limiting the lateral 'movement of the carriage 27 withinsaid sleeve. A short shaft 33is rotatably and slidably mounted in thecarriage 27 and is provided at its inner end with a small spiral pinion34, preferably integral therewith. A similar pinion 35, preferablylarger in diameter, is mounted upon the shaft adjacent its outer end andis adapted to engage an internal spiral gear 36 rigidly mounted withinthe differential. housing by suitable means, such as keys or pins 37. Anannular recess 40 is provided at the outer ends of the hubs of thedifferential case 15 to provide clearance for the pinion 35 whendisengaged from'the gear 36. A pair of internal spiral gears 38 are alsoprovided within the spider 17, and are preferably integrally formedtherewith, and adapted to receive the spiral pinions 34.

Referring to Figure 1, it will be noted that the pinion 35 and gear 36,shown on the right hand side of the figure are both left hand spirals,while the corresponding pinion and gear on the left hand side of thefigure are right hand spirals. Also the pinion 34 and gear 38, shown onthe right hand side of the figure, are right hand, while thecorresponding pinion and gear on the left hand side of the figure areboth left hand spirals.

' On the right hand side of the above figure 2 25 rotate at synchronousspeed, as when the vehicle is traveling in a straight line, while thecarriage will increase its rotation with reference to the spider whenturning to the left, and decrease its speed when turning tothe right,due to being directly connectedto the differential side pinion 21 bymeans of the pins 28 andapertures 29. t-

Assuming now that the driven wheel on the right hand side of the vehicleengages a slippery spot in the road surface and starts to idle or spin;the speed ratio between the. spider' 17 and the carriage 27 will change,caused by the usual differential action of the side pinion 21 and thedifferential pinions 19. The result of this action will cause the sleeveand carriage to rotate at an exceedingly high speed, with reference tothe spider, and the pinion 34 being in engagement with the gear 38 willstart to rotate the shaft 33 in its bearings in the carriage, therebyrotating the pinion 35 in the reverse direction to the carriage. Themeans for shifting the pinion 35 intoengagement with the gear 36 isaccomplished by the angle of the teeth in the pinion 34 and the" pinion34 to move outwardly 'as it rolls around in the gear 38, but is held bythe outer ends of the teeth in thepinion 35 engaging the inner ends ofthe teeth inthe gear 36. However, as soon as the peripheral speed of thepinion 35 allows it to slide into engagement with the gear 36, the shaft33, carrying the pinions 34.and 35, will be moved outwardly to theposition shown on the left hand-sideof Figure 1, thereby securelylocking the driven member 25 to the gear 38. This angle is such as tocause the spider 17 and thus preventing said member w from furtheridling, the power from the motor being transmitted through the. shaft 33to the driven member 25. "ft L 5 soon as the rotation of the wheeltending to idle, has been reduced to normal, the pinion .35 rolling inth gear 36 will be moved inwardly out of engagement with said gear, dueto the angularitv of the teeth, and the carriage and spider rotating atthe same speed, will permit the pinion 34 to .be returned to its normalposition in full engagement with the gear 38.

Means are also provided to positively prevent both sides of thedifferential from functioning simultaneously when the vehicle isreversed. By referring to Figure 1, it will be readily seen that as thedifferential spider 17 starts to reverse, it will disengage both pinions34 from the gears 38, due to the angularity of their teeth, and slidethe pinions 35 into engagement with the stationary gears 36, therebylocking both sides of the differential at the same time which wouldcause the entire rear axle to become lnopera-z 1 five. Means aretherefore provided whereby the above condition may be positivelyeliminated.

Diagonal passages or openings 39 are prefgrooves 31 and 32, as shown inFigures 5 and 6, then function being to permit the -erably provided inthe Walls between the pins 28 to pass from one groove to the othermembers. mounted for relative rotation, gear as the vehicle is movedforwardly or rearwardly. As soon as the vehicle starts a reversemovement the two carriages 27, due to the action of the teeth in thepinions 34 and gears 38, will tend to move outwardly, and as the pins 28traveling in the grooves 31 engage the passages 39, they will passthrough said passages to the grooves 32,'thus moving the two carriagesoutwardly and permitting the pinions 34 to become disengaged from thegears 38- When in this position, the pinions 35 will be in fullengagement with the stationary gears 36, as shown in Figure 2. Shouldone driven member start to idle during the reverse movement of thevehicle the mechanism will function as hereinbefore described. As soonas the vehicle again starts a forward movement, the. pins 28 will passfrom the grooves 32 through the passages '39 to the grooves 31, therebyrestoring the carriages to their normal positions as shown in Figure 1.

I claim as my invention:

1. diiferential gearing comprising members mounted for relativerotation, a spiral gear mechanism, and means co-operable therewith upona predetermined racing ofeither member positively to drive the othermember.

2. A difierential gearing comprising members mounted for relativerotation, spiral gears mounted to .slidetowardand from said members, andstationary means adapted to be engaged by said spiral gears upon apredetermined racing of either member positively to rotate theother'member.

3. A differential gearing comprising a housing, members mounted forrelative rotation therein. spiral gears mounted in said housing andaxially movable therein, and means adapted to be engaged by the spiralgears upon a predetermined racing of either member member.

4. A difi'erential gearing comprising members mounted for relativerotation, a sleeve secured to each member and concentrically revolubletherewith, and a spiral gear mechanism automatically operable upon apredetermined relative movement and sleeves, gear rings carried by thespider,-

stationary gear rings encircling the sleeves, andpinions mountedformovement into or out of mesh with the spider rings for reducing theidling speed of either member when it exceeds a predetermined periphealspeed.

6. A. differential gearing, comprising positively to drive the other.

pinions and i sleeves thereon, a revolving spider interposed betweensaid gear pinions and sleeves, spiral gear rings mounted in said spider,stationary gear rings encircling said sleeves, and spiral pinlonsmounted for movement into or out of mesh with said spiral rings, forreducing the idling speed of either member when it exceeds apredetermined peripheral speed, or releasing said member.'

7. A differential gearing comprising members mounted for relativerotation, gear pinions having sleeves thereon to revolve therewith, aspiderinterposed between said sleeves and having driving connection withsaid pinions, spiral gear rings mounted in said spider, carriagesmounted to slide in said sleeves, stationary spiral gear ring-s, spiralpinions mounted in said carriages to engage respectively said stationarygear rings and said spider gear rings, for reducing the idling speed ofeither member when it exceeds a predetermined peripheral speed.

8. A differentials gearing, comprising members mounted for relativerotation, revolving and stationary spiral gear rings,

spiral gear pinions mounted to mesh respectively with said gear rings,and having an axial movement toward and from said gear rings to meshtherewith or be separated therefrom for controlling the idling speed ofeither member, and means permitting the disengagement completely of saidspiral gear pinions from said revolving gear rings when saiddifferential is reversed.

I 9. A differential gearing, comprising members mounted forrelativerotation, revolving and stationary spiral gear rings, spiral gearpinions mounted to mesh respectively with said gear rings, and having anaxial movement toward and from said gear rings to mesh therewith or beseparated therefrom for controlling the idling speed of either member,and means permitting the disengagement completely of said spiral gearpinions from said revolving gear rings when said differential isreversed, said means including annular grooves having slotted flangesbetween them, and pins mounted to slide in said grooves and pass throughsaid slots from one groove to the other when the gear ring is reversed.

10. A difierential gearing, comprising members mounted for relativerotation, slid ing carriages, means mounted in said carriages forreducin the idling speed of either member when sai member reaches apredetermined peripheral speed, a housing having annular groovestherein, and slotted flanges between said grooves, and pins mounted insaid carriages to slide in' said grooves and pass through said slotsfrom one groove to the other when said gearing is reversed.

11. A differential gearing comprising members mounted for relativerotation, mechanism operable difi'erentially to drive the members,slidable carriages, means on the carriages co-operable with saidmechanism and operable upon a predetermined racing of either memberpositively to drive I the other member, an element having a spiral gearmechanism, upon reversing of the gearing, to maintain operative saidpositive drive means.

13. A difi'erential members mounted for comprising gearing v rotation,

relative .meehanism operable differentially to drive.

the members, slidable carriages, means on each carriage co-operable withsaid mechanism and operable upon a predetermined racing of either memberpositively to drive the other member, an element having a set ofintercommunicating annular grooves adjacent each carriage, means on eachcarriage co-operable Wltllll'S adjacent set of grooves to maintain itsslidablc carriage in normal position, and each carriage means beingadapted to pass from one to another of the intercommunicating grooves ofa set upon reversal whereby said positive drive is maintained operativeduring reversal.

In Witness whereof, I have hereunto set my hand this 6th day of Sept,1922.

JOHN'FR. MORRISSEY.

